Cloud Selections are found in the main upper toolbar under 'Home > Selection'.
Select All
Selects all visible scan points.
Clear Selection
Clears (or deselects) selected points from all visible scans.
Invert Selection
Inverts a selection. Selected points will become deselected and points that were not selected will now be selected.
Note: The tools above are grayed out by default. To make them active, the Shape tool must be in one of the 4 “Area Selection” modes.